Continuous electrolytic process for reducing uranium in solution



Dec. 25, 1956 R. Q. BOYER commuous ELECTROLYTIC PROCESS FOR REDUCING URANIUM IN SOLUTION Original Filed April 21; 1944 3 Sheets-Sheet l a 3 Q 6 x M M/ 4 m. l w 6m U. 5

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w 1 U m M Q3 1 Mm nhm W9 0 J l -5 2 n w w Q 2 Z a a w I 1 9'. 36 37 38a 28 3a 39 30 3/ 30 3/229 28 INVENTOR. ROBERT 0. B0 YER W4 M ATTORNEY 1956 R. Q. BOYER 7 2,775,552

. CONTINUOUS ELECTROLYTIC PROCESS FOR I REDUCING URANIUM IN SOLUTION (-riginal Filed April 21, 1944 5 Sheets-Sheet 2 IN V EN TOR. R055? 7 Q. 50 YER BY r Wim- Dec. 25, 1956 R. BOYER 2,775,552

CONTINUOUS ELECTROLYTIC PROCESS FOR REDUCING URANIUM IN sownou Original Filed April 21, 1944 3 Sheets-Sheet 5 g INVENTOR.

g g -Q ROBERT Qborm I BY Ma M l United States Patent O CONTINUOUS ELECTROLYTIC PROCESS FOR REDUCING URANIUM IN SOLUTION Robert Q. Boyer, Berkeley, Calif., assignor to the United States of America as represented by the United States Atomic Energy Commission Original application April 21, 1944, Serial No. 532,162. Divided and this application September 10, 1945, Serial No. 615,467

3 Claims. (Cl. 204-124) The present invention relates to uranium reclamation processes and, more particularly, to such processes including the continuous electrolytic reduction of oxidized acidic aqueous chloride solutions of uranium. The present application is a division of my copending application, Serial No. 532,162, filed April 21, 1944, and now Patent No. 2,743,228, granted April 24, 1956.

In the copending application of Ernest 0. Lawrence, Serial No. 557,784, filed October 9, 1944, and now Patent No. 2,709,222, granted May 24, 1955, there is dis-' closed a calutron, a machine designed to separate the constituent isotopes of an element and more particularly to increase the proportion of a selected isotope in an element containing several isotopes, in order to produce the element enriched with the selected isotope.

In the copending application of James M. Carter an Martin D. Kamen, Serial No. 532,159, filed April 21, 1944, and now Patent No. 2,758,006, granted August 7,

1956, there is disclosed a method for processing uranium in a calut-ron, wherein there is produced a variety of composite aqueous uranium solutions.

In the copending application of Martin D. Kamen and Abel de Haan, Serial No. 542,378, filed June 27, 1944, there is disclosed an improved process of purifying a composite solution of the character mentioned in order to separate uranium from metal impurities in the solution. In accordance with this process, a composite solution comprising UO2++, Cu Ni++, Fe+++ and Cr+++ ions is first acidified with HCl and then reduced electrolytically, whereby the uranyl' ion, UO2++, and the ferric ion, Fe+++, are respectively reduced to the uranous ion, U++++, and the ferrous ion, Fe++. Thus the reduced solution contains U++++, Cu++, Ni+.+, Fe++ and Cr+++ ions. To the reduced solution there is added oxalic acid, whereby the uranium is precipitated as thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawings in which Figure l is a fragmentary plan view of an electrolytic cell in which there may be carried out the process of the present invention; Fig. 2 is a fragmentary longitudinal sectional view of the electrolytic cell taken along the line 22 in Fig. 1; Fig. 3 is a transverse sectional view of the electrolytic cell taken along the line 3-3 in Fig. 2; Fig. 4 is a transverse sectional view of the electrolytic cell taken along the line 44 in Fig. 2; and Fig. 5 is a diagrammatic illustration 16 being congruent.

2,775,552 Patented Dec. 25, 1956 of a solution treatment system in which the electrolytic cell is incorporated.

Referring now more particularly to Figs. 1 to 4, inclusive, of the'drawings, there is illustrated an electrolytic cell 10 which is suitable for carrying out the processes of the present invention and comprising a lower casing section 11 and an upper casing section 12. The lower casing section 11 is substantially rectangular in plan, includinga fiat bottom wall 13, upstanding side walls 14 and upstanding end walls 15, secured together in liquid-tight relation, the perimeter of the bottom wall 13 being received in interior grooves formed in the side walls 14 and in the end walls 15 adjacent the lower edges thereof. Further, the lower casing section 11 includes a rectangular outwardly extending flange 16 disposed about the upper open end thereof and rigidly secured to the adjacent outer surfaces of the side walls 14 and the end walls 15. Similarly, the upper casing section 12 is substantially rectangular in plan, including a flat bottom wall 17, upstanding side walls 18 and upstanding end walls 19, secured together in liquid-tight relation, the lower edges of theside walls 18 and the end walls 19 being received in a rectangular groove formed in the upper surface of the bottom wall 17, and disposed inwardly from the perimeter thereof. Accordingly, the bottom wall 17 of the upper casing section 12 extends outwardly from the side walls the upper casing section 12 are formed of laminated phenol-aldehyde resins such as Bakelite, Textolite or other similar insulating material.

The upper casing section 12 is assembled upon the lower casing section 11, the rectangular flanges 20 and Also, a sealing gasket 21, formed of rubber or the like, is arranged between the lower surfaceof the bottom wall 17 and the upper edge of the side walls 14 and the end walls 15, and extending between the flanges 20 and 16. Finally, the flanges 16 and 20 are removably secured together in liquid-tight relation by a series of bolts 22, extending through aligned openings formed therein, the ends of the bolts 22 receiving nuts 23. Washers 24 and 25 surround the shanks of the bolts 22 and are respectively disposed between the heads of the bolts 22 and the upper surface of the flange 20, and between the nuts 23 and the lower surface of the flange 16. Further, a drain pipe 26 is threaded in an opening formed in the bottom wall 13 adjacent the left-hand end wall 15, which drain pipe communicates with the interior of the lower casing section 11. The end of the drain pipe 26 terminates in a petcock 27, whereby the drain pipe 26 may be selectively opened or closed.

A number of laterally extending and longitudinally spaced apart slots 17a are provided through the bottom wall 17 within the area bounded by the side walls 18 and the end walls 19; and a corresponding plurality of upstanding laterally extending and longitudinally spaced apart pairs of partition elements 28 are carried by the upper surface of the bottom wall 17, the individual partition elements 28 of each pair being disposed on the opposite side of a slot 17a. More particularly, each upstanding partition element 28 is retained in place by a pair of aligned upstanding slots 18a, formed in the inner surfaces of the side walls 18, and an aligned laterally extending recess 17b, formed in the upper surface of the bottom wall 17 adjacent a slot 17a. Thus, each partition element 28 is retained in place in upstanding position by a substantially U-shaped composite groove comprising a pair of upstanding slots 18a formed in the inner I surfaces of the side walls 18 and a cooperating'laterally extending recess 17b formed in the upper surface of the bottom wall 17; Finally, an upstanding laterally'extending partition element 29 is carried by the upper surface of the bottom wall 17, the partition element 29 being spaced longitudinally and to the right-hand side. of thepartition element 28 disposed mostrernote from the left-hand end wall 19. Also, the upstanding partition element 29 is retained in place by a pair of upstanding cooperating slots formed in the inner surfaces of the side walls 18 and an aligned-laterally extending recess formed in the upper surface of the bottom wall 17, in a manner identical to that previously explained in conjunctionwith each partition element 28.

The various partition elements 28 and the partition element 29 comprise rectangular plates formed ,of a porous semipermeable insulating material of the ceramic type; such as alundumor sintered Pyrex glass; Collectiv'ely; thepairs of partitionelements 28' and thepartition element 29 constitute partition structure defining a plurality of-interposed anode-and cathode compartments 30 and 31, respectively,--in the upper casing-section 12;

i and secured together -.and to the bottom ;wall ;17;.by1:the:

More particularly, the two partitionelements-ZS ofeach pair. cooperate with each other and with'the portions of -the-side walls 18,. disposed therebetween to define-a cathode-compartment -31 having an open lowerend formed bya cooperating slot-17a. Similarly, eachlefthand: partition element 28 of a pair cooperates with the adjacent right-hand: partition element-28 of a pair and with.the portions of the side walls :18. and thebottom-' wallt17 disposed therebetween to :define an anode compartment-.30 having a closed lower end. -Further,:-the-- left-handapartition element 28 of the pair disposed adjacenttthe left-hand end wall l9rcooperates therewith andv with the portions of the side walls .18 and .the bottom.

wall 17 disposed therebetween. to define the. anode compartmentfitldisposed immediately adjacent the left-hand end wall 19. Finally, theright-hand partition element 28 0f the pair disposed adjacent the partition element 29 cooperates therewith andwith the portions of the side walls-18' and the,bottom wall 17 disposed therebetween. I

to .define the anodecompartment 30 disposed most remoteifrorn the left-hand end wall 19.

The upper edges of the various pairs of partition elements 28 and the partitionelement 29 are disposed substantially flush with the-upper edges of the side walls 18,

and the upper edgesof the side walls 18 are substantially flush with the upper edges of the end walls 19; whereby the upper edge of the upper casing section 12 is substantially flat and parallel to the bottom wall 13 of the lower casing section 11. Further, a pair of conductors in theform of busbars 32, formed of copper or the like,

aresecured, to the vupper edges of the, side walls 18 by z a number of screws 33. The left-hand ends of the busbars 32 are;securedv together by a conducting strap 34 byf screws 35; and, a conducting terminal 36 is secured to the mid-portion of the strap 34 by a screw 37. A plurality of lanodejelements 38 is carried by the busbars 32 and; arranged in the respective anode compartments 30. Each of the anode elements 38comprises a substantially. rectangularplate provided at its upper end with laterally.

and oppositely extending lugs 38a which overhang the respective' busbars 32. The anode elements 38 are formed 7 of a conducting material resistant to chlorine and hydro-. chloric acidjsolutions, such as graphite, and-are electr i-,

callyfeonnected to the busbars32 by terminal structure including screws 39 and flexible conductors 40. More operatinganodeelement 38.- Thus, the terminal 36 is connected by low-resistance paths toeach of the anode elements 38 in multiple, whereby collectively the. anode elements 38 constitute an anode.

A longitudinally extending shaft 41 is rotatably mounted in two bearing brackets 42 and 43, securedto the and spaced some distance from the right-handend wall- 15. The bearing brackets 42 and 43may suitably -com-' prise complementary sections formed of stainless steel screwst44zandv45, aspreviouslynoted. The shaft 41 carries a plurality of longitudinally spaced apart: cathode members 46 in the form of disks. Each of the cathode members 46 is rigidly secured to the shaft 41, so that it is rotatable therewith, and extends downwardly into the lower casing section 11 and upwardly through-a cooperating one of the slots 17a into a cooperatingone of the cathode compartments '31forrned'in -the P31111101) structure within the uppercasing section 12. -Thecathode= members 46 =are formed of a conducting material resistant to chlorine and hydrochloric acid solutions that readily amalgamates with mercury, such, for example, as a nickel. The cathode-members 46.areelectrically-connected to the shaft 41 in'multiple-and collectively constitute a cathode.

A laterally extending-opening is provided throughthfiwbOttOll'l wall 17 adjacent-the right-hand end wall -19; and-a bevel gear 47-is rigidly secured to the right-hand endof the shaft 41, wherebyt'he upperportion ofthe bevel: gear 47 extends upwardly through the opening 170 intothe upper casing section 12, and thellower portion of the bevel gear 47- extends downwardly into the lower casing sectionll. More particularly, the bevel gear 47 -is provided with a collar 48 whichis secured to the right-hand end ofttheshaft 41 by asetscrew-49.and-carries a flange 1.. 50 engaging the right-hand side ofthe bearingbracket 431;

to provide a thrust bearingv for the shaft ,4l.

carried by. a bearing strap..56. i More particularly, the

bearing bracket 54icomprisesstwolaterally upwardly and outwardly extending legs 57, which aresecuredby screws 58-10 the .lower surface of the bottom. wall 17, and a longitudinally, upwardly and outwardly extending. leg .59,

WhiQh;iS securedby the screwsAS .to the bearingbracket 43: The gthrust bearing '53 7 comprises a threaded. step 60: accommodating adjustment. of the operating shaft, 52in the:.v.ertical direction,.andconsequently proper mesh :b

tweentthahevel gear .SLcarried. thereby andthe bevel gear: carried-by the; shaft 41. The bearing strip .56extends. laterally;across the upper casing section 12,..and theopw.. posite ends thereof are suitably anchored to the upper-,1

edges-of the side walls 18 by screws 61.

A pool .Qfmercurv62 is arranged in the lower casingn section 11, the mass of the mercury-pool being, such that .1.

columns of mercuryrise in the slots,17a into, thecathode compartments; 3l. Preferably, the columns 10f mereuryi rise; int o-'the cathode compartments 31a slight distaucers. a'bovethe upper surface of the bottom Wfl1l.17,- whereby; the shaftgfll andthe lower segments of the-cathode mem: bers 46-are,-immersed in the mercury pool 62. An -up-. standing, cathode plate 63 extends through the, upper. cas-..

inggsection 12 downwardly through the opening17c and I terminates; in the lower casing section 11,- whereby. the lowercend; ofgthe cathode plate 63 is immersed in the, mercury 1109162., A substantially: U-shaped ,clip 64 ,is rigidly securedto the cathode plate 63 and is adaptedto overhangjthe adjacent. upperv edge of the right-handend wall 19, thereby securely to retain the cathode plate 63 in position.

Further, a body of electrolyte 65 is arranged in the upper casing section 12 as a head upon the mercury pool 62, the body of electrolyte 65 filling the various anode and cathode compartments 30 and 31, respectively, and electrically communicating through the porous partition structure including the partition elements 28 and 29, the mass of the body of electrolyte 65 being such that the upper segments-of the cathode members 46 are completely immersed therein. The cathode compartments 31 in the upper casing section 12 are arranged in groups, each group containing several adjacent individual cathode compartments, the individual cathode compartments in each group being connected in series relation by a conduit system, and the different groups of cathode compartments being connected in parallel relation by the conduit system.

Considering now the illustrated embodiment of the electrolytic cell in greater detail, the partition structure comprises nine pairs of partition elements 28, whereby nine individual cathode compartments 31 are formed in the upper casing section 12 and arranged in longitudinally spaced apart relation, each of the cathode compartments 31 communicating through the associated slot 17a with the lower casing section 11. Also, the rotatably mounted shaft 41 carries nine longitudinally spaced apart cathode members 46 which extend through the respective slots 17a into the respective cathode compartments 31. Further, the partition structure comprising the nine pairs of partition elements 28 and the partition element 29 forms ten individual anode compartments 30 in the upper casing section 12, arranged in longitudinally spaced apart relation and in interposed relation with respect to the cathode compartments 31. Thus, in the partition structure an anode compartment 30 is positioned on either side of each cathode compartment 31. The nine cathode compartments 31 are arranged in three groups of three individual cathode compartments each; the three groups of cathode compartments 31 are connected in multiple by the the conduit system mentioned; and the three individual cathode compartments 31 in each group are connected in series by the conduit system mentioned.

Referring now more particularly to Figs. 1, 2 and 5, the conduit system mentioned comprises three inlet pipes 101, respectively serving the three groups of cathode compartments 31 and respectively communicating with the first, fourth and seventh individual cathode compartments 31; positioned from the top of the electrolytic cell 10 toward the bottom thereof, as viewed in Fig. 5, and from the righthand side of the electrolytic cell 10 toward the left-hand side thereof, as viewed in Fig. 1. Also, the conduit system mentioned comprises three outlet pipes 102, respectively serving the three groups of cathode compartments 31 and respectively communicating with the third, sixth and ninth individual cathode compartments 31. The adjacent right-hand ends of the first and intermediate individual cathode compartments 31 in each group are connected together by U-shaped header pipes 103, the adjacent right-hand ends of the first, second and fourth, fifth and seventh, eighth individual cathode compartments 31 in the electrolytic cell 10 being so connected by the header pipes 103. The adjacent left-hand ends of the intermediate and last cathode compartments 31 in each group are connected together by U-shaped header pipes 104, the adjacent left-hand ends of the second, third and fifth, sixth and eighth, ninth individual cathode compartments 31 in the electrolytic cell 10 being so connected by the header pipes 104. In conjunction with the conduit system, it is noted that a series of aligned openings 18b are formed in the side walls 18 and communicate with the cathode compartments 31 in order to receive the various pipes 101, 102, 103 and 104, the openings 18b being disposed above the cathode members 46 so that the upper segments of the cathode members are completely immersed in the body of electrolyte 65.

Accordingly, it will be understood that a first stream" of electrolyte may be conducted from a first of the inlet pipes 101 through the first cathode compartment, viaa first of the header pipes 103, through the second cathode compartment, via a first of the header pipes 104, and

through the third cathode compartment to a first of the outlet pipes 102. Similarly, asecond stream of electrolyte may be conducted from a second of the inlet pipes 101 through the fourth cathode compartment, via a second of the header pipes 103, through the fifth cathode compartment, via a second of the header pipes 104, and through i the sixth cathode compartment to a second of the outlet pipes 102. Finally, a third stream of electrolyte may be conducted from a third of the inlet pipes 101 through Thus, the conduit system connects the individual cathode compartments 31 in the electrolytic cell 10 in parallel series relation.

Considering now the arrangement of the solution treatment system in greater detail, reference is made to Fig. 5. The operating shaft 52 is suitably connected to a motor 105, which is preferably of the electric type;

the cathode plate 63 is connected to the negative terminal of a source of direct current supply; and the terminal 36 is connected to the positive terminal of the source of direct current supply. Thus, when the motor is operated, the operating shaft 52 is rotated,

causing the bevel gear 51 to drive the bevel gear 47 in order to rotate the shaft 41. As the shaft 41 is rotated, the cathode members 46 are rotated, whereby repeatedly the lower segment of each of the cathode members or disks 46 is removed from the mercury pool 62 and immersed in the body of electrolyte 65 in the associated one of the cathode compartments 31, and the upper segment thereof is removed from the body of electrolyte 65 in the associated one of the cathode compartments 31 and immersed in the mercury pool 62. The motor 105 is operated at a suitable speed in view of the gear reduction ratio between the bevel gear 51 and the bevel gear 47, so that the shaft 41 and consequently the disks 46 rotate at the required speed, as explained more fully hereinafter.

Each of the inlet pipes 101 terminates in a funnel 106; and each of the outlet pipes 102 terminates in an outlet header 107. Also, the conduit system comprises an inlet header 108 provided with three branches 109, which respectively feed the three funnels 106 respectively terminating the three inlet pipes 101. More particularly, each of the branches 109 is provided with an adjustable petcock 110, whereby the flow of electrolyte therefrom into the associated funnel 106 may be selectively controlled. Finally, the conduit system comprises a supply receptacle 111, a storage receptacle 112, a pressure regulator 113, and a pressure conduit 114. One end of the pressure conduit 114 is connected to a source of air under pressure, not shown; and the other end of the pressure conduit 114 terminates in the supply receptacle 111. Also, the mid-section of the pressure conduit 114 is connected to an upstanding tube 115 extending into the pressure regulator 113. More particularly, the pressure regulator 113 comprises a vessel 116 containing a column of mercury 117, into which the upstanding tube 115 extends, the lower end of the upstanding tube 115 being submerged the required depth in the column of mercury 117 in order to establish a corresponding predetermined blow-out pressure in the vessel 116. The upper end of the vessel 116 is closed by a stopper 118, through which a vent pipe 119 extends. It will be understood that the pressure regulator 1 13 maintains the previously mentioned pressure in the end of the pressure conduit 114 extending into the supply receptacle 111. In the event the pressure in the pressuregconduit,114;exceeds ithe -,predet.e,12m ncd,

pressure';mentioned,,,air,is blown through theupstandin'g tube 115 ,against; the predetermined column lof mercury; 117 into, the upper portion ofthe vessel116, and-,vented to the, atmosphere -via the-vent -pipe..119 whereby. the

airpressure ,in the .pressure conduit 114.,is maintained at the required value.

The supply, receptacle 111 is in the formof a bottle; the. throat of-which is closed-by' a stopper 120; thrqugh which thepressure -.conduit,114 extends,"the;.lower-end of lthe pressure, conduit 114 terminating adjacent the top:;of .thesupplyreceptacle 111. -Also,,; the ;supply receptacle 111 contains a quantity of electrolyte 121v which is to be conducted throug zthe electrolytiexcelle;

10 to-thestorage receptacle 112. A conduit 122 ,extends,

through;;the stopper 1120;;andgconnects the supply receptacle 111,to the inlet header. 108, one end of the conduit 122 being,connected;to .theinletheader 108 and the other end of the conduit 122 terminating in the supply.

receptacle 111: adjacentv the; bottom thereofi; Finally,

the outlet header 107 is connected by a conduit,123 .to

the; ;st0rage receptacle 112, one endqofzthe conduitg123.

being connected to the-outlet header'107 and the other. end of the. conduit 123 terminatingwin the. storage. -.re-p

ceptacle .112 vadjacent the top thereof. The. storage receptacle 112 is in the form of a bottle, the throat of duitsystem through the electrolytic cell 10, it will be understood that a predetermined regulated pressure is maintained by the pressure regulator 113 in .thepressure conduit.114, whereby the regulated pressure :is maintained in the upper portion of the supply receptacle,111.- The pressure maintained in the upper portion of the supply receptacle 111 as a head over the quantity of electrolyte 121 therein, forces the electrolyte through the conduit 122 into the inlet header 108,- and consequently into the three branches 109. The petcocks'110,

are; appropriately adjusted, whereby three streams. of electrolyte are delivered into the three associated funnels 106, causing the required static head of electrolyte to be maintained in the three inlet pipes 101; Theelectrolyte flows from the three inlet pipes 101 through the three groups of cathode compartments 31, in .parallel series relation in the electrolytic cell 10, into the outlet pipes 102, in the mannerpreviously explained. The electrolyte then flows from the outlet pipes 102 into the outlet-iheader 107, and therefrom through the conduit 123 into the storage receptacle 112. As the electrolyte 126 is delivered to the storage receptacle 112, air therein is vented through the vent pipe 125 to theatmosphere.

Considering, now the construction and, arrangement of the component elements 'ofthe electrolytic cell 10 in greaterdetail, reference is again made to Figs. 1 to 4 inclusive, and it is noted that in the specific embodiment of the electrolytic cell .10 illustrated, .each of the disks has a diameter approximately 12 cm. and approximately 40%. and of its area are respectively immersedin the body-of electrolyte and in the mercury pool 62.-.i Thus, about cm. of the-area of each of the disks: 46- is immersed in the body ,of electrolyte ,65, whereby the total area of the cathode immersed in the bodyof electrolyte 65 is approximately 720 cm. Employing-an electrolyte constituting a hydrochloric acid solution," electrolytic currents 'Within the range to amperes; have been obtained, whereby the electrolytic current was approximately 0.2- ampere :per cm? of the, area of .the cathode, which-value is well within the usual operatinglimits, 0.1, to .0.3 ampere per, cm. at the cathode,,.for electrolytic. cells. The electrolytic current;

mentioned.was obtained {when several volts, 'about four,....

direct current was applied between the cathode .plate, 63 and the anode terminal 36. Underthe operatingconditions. mentioned, it was found that threestreams of electrolyte conductedthrough. thethree groups :of;-. cathode compartments -31 of reasonable volume permitted operationwithout undue heating of eitherv the ,electrolytic cell 10 or the=electrolyte. More-particularly, each.,,. of the three streams of electrolyte comprised a flow of approximately 50 cc. per minute, the temperature. rise,v of the electrolyte being of the order of 55.C. Speci-..

fically, 150 cc. ofelectrolyte per minute were conducted.

through the cell, experiencing a temperature rise. from, 1520 ,C. to 7075 .C. When .the electrolyte. was;

conducted through the electrolytic cell 10 at the rateand under theoperating conditions mentioned, there -.was no.

undue heating of the component'parts of the electrolytic,

cell.

Now consideringtheaoperation of theelectrolytic cells.

10 in conjunction with the solution treatment system. in carrying out the processes of the present invention it.

is noted that the anode and cathode compartments 30 and 31 are initially filled with a body of electrolyte 65 comprising about 3 N HCl; then the solution to be treated is conducted from the supply receptacle 111 through the; cathode compartments 31 operating under the conditions specified; whereby the initial body of electrolyte 65 in the cathode compartments 31 is at least partially dis- 1 placed by the ,solution which thenbecomes, part of the electrolyte in the cathode compartments 31. Specifically, the solution which is conducted from the supply..;

recepticle .111 is about 3 N HCl and contains UOzH', Fe+++, Cu+ Ni and Cr+++ ions. This hydrochloric, acid solution is prepared in the manner disclosedin the previously mentioned copending application of Kamen. and De Haan;.which acidsolution comprisesa wash solu-,

tion produced in the manner disclosed in the previously,.. mentioned copending application of Carter and Kamen; which wash solution is derived froma calutron of the character of that disclosed in the previously mentioned and the ferric ion, Fe+++, are respectively reduced by the electrolytic current to the uranous ion, U++++, and Of course it will be understood that .a small amount of the ions Cu++, Ni++, Fe++ and the ferrous ion, Fe++.

Cr+++ are completely reduced to the metal states Cu", Ni, Fe and Cr by the electrolytic current, which metal impurities in the body of electrolyte 65 are carried by 1 the rotating disks 46 into the mercury pool 62. It will j be understood that by suitably altering the operating con- 1 ditions, such as by reducing the rate of flow of electrolyte through the cell and/or by increasing the current.v

density, the reduction of ions other than U++++ to the metal state may be made substantially complete, if desired. The metal impurities carried into the mercury,-

pool 62.by the rotating disks 46 areeither trapped therein or amalgamated therewith, whereby the body of electro lyte 65 is kept free of metal impurities liberated therein incident to the electrolysis. Specifically, the copper, chromium and nickel impurities readily amalgamate with the mercury pool 62, whereas the iron impurity is trapped therein. On the other hand, none of the uranous ion,

U++++, is completely reduced to the metal state, U due to the fact that it inherently possesses a high over-voltage.

Further, it will be understood that the rotation of the disks 46 is efiective not only to carry the. metal impurin... ties from, the body ofelectrolyte 65 into the mercury, pool 62 in the manner previously explained, butit also};

agitates the body of electrolyte 65 and the mercury pool 62 inorder to facilitate the electrolysis. Finally, the constant rotation ofthe disks 45 causes a freshly amalgamated surface thereof to be presented from the mercury. pool 62 to the body of electrolyte 65, thereby maintaining substantially constant the internal resistance of the electrolytic cell and consequently the electrolytic current therethrough. Under the operating conditions specified the electrolytic cell 10 requires no separate cooling system.

Incident to operation of the electrolytic cell 10, the anion CF migrates through the partition elements 28 to the anode elements 38 disposed in the anode compartments 30, whereby some C12 gas is liberated and escapes from the anode compartments 30 to the atmosphere. Of course some of this chlorine gas is trapped in the electrolyte disposed in the anode compartment 30; however, substantially none of it migrates through the porous partition elements 28 into the electrolyte disposed in the cathode compartment 31, due to the character of the porous partition elements 28, the porosity of the partition elements 28 accommodating conduction of the electrolyte and consequently the electrolytic current therethrough, but substantially preventing the migration of the chlorine therethrough whether in the vapor phase or in solution in the electrolyte. This arrangement is very advantageous, in view of the fact that the chlorine does not contaminate the electrolyte disposed in the cathode compartments 31, whereby the oxidizing effect of chlorine on the ions in the cathode compartments 31 is eliminated. Of course it will be understood that chlorine gas possesses a high oxidizing potential and is capable readily of oxidizing the uranous ion, U++++, back to the uranyl ion, UO2++, as well as Fe++ back to Fe+++, thereby preventing efficient operation of the electrolytic cell 10. However, this difiiculty is overcome clue to the construction of the partition structure mentioned, whereby the electrolytic cell 10 operates etn'ciently substantially entirely to reduce the uranyl and ferric ions to the uranous and ferrous ions, as previously noted.

After the electrolytic cell has been employed to treat a predetermined quantity of chloride solution in order to reduce the contained ions in the manner previously explained, the mercury pool 62 becomes somewhat contaminated with the metal impurities mentioned. At this time, the petcock 27 may be opened, allowing the mercury pool 62 disposed in the lower casing section '11 and the body of electrolyte 65 remaining in the cathode compartments 31 in the upper casing section 12 to be drained therefrom and conserved. The body of electrolyte 65 remaining in the anode compartments '30 in the upper casing section 12 may be drained therefrom in any suitable manner and discarded; for example, such electrolyte may be siphoned out of the anode compartments 30. The conserved electrolyte is then returned to the supply receptacle 11 1 to be treated subsequently, and the mercury is reconditioned in order -to eliminate the amalgamated and trapped metal impurities. Also, at this time the other component parts of the electrolytic cell 10 may be cleaned, thereby reconditioning the cell for further use. Thereafter, the required amount of fresh mercury is poured back into the lower casing section 11 through the opening 170 formed in the bottom wall 17, in order to form a new mercury pool 62 of the character specified. A quantity of electrolyte, 3 N HCl, is poured into the upper casing section 12 through the open top in order to form a body of electrolyte 65 as a head on the mercury pool 62 and to fill the anode and cathode compartments 30 and 31, respectively, in the manner previously explained. At this time, the electro- 'lytic cell 10 is conditioned for subsequent operation in the manner previously noted.

It is pointed out that the quantity of chloride solution 126 contained in the storage receptacle 112 which has been treated or reduced in the electrolytic cell 10 is subsequently subjected to a suitable purification treatment in order to recover the contained uranium, such, for examing application of Kamen and De Haan.

The term uranium is employed in the present specification in a generic sense, without reference to whether it is present in the free or combined states, unless indicated otherwise by the context.

In view of the foregoing, it be apparent that there has been provided an improved process, which is especially adapted for use in conjunction with the reduction of uranium solutions incident to the purification of wash solutions derived from calutrons.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. In a process for reclaiming uranium values from an oxidized hydrochloric acid solution of about 3 N concentration and containing UO2++ ions and ions selected from the group consisting of Fe+++, Cu++, Ni++, and Cr+++ ions, the steps comprising continuously passing said solution through the cathode compartment of an operating electrolytic cell having a rotating cathode which is provided with a thin, continuously-replaceable mercury coating and an anode compartment filled with a hydrochloric acid electrolyte of about 3 N concentration and separated from said cathode compartment by a porous barrier, continuously and simultaneously correlating the rate of flow of said solution through said cathode compartment of the operating cell with the electrolytic current density applied therethrough to promote the reduction of the UO2++ ions to U++++ ions and the reduction of ions of said group to the metallic state and which are absorbed in said mercury cathode coating, and simultaneously and continuously replacing said mercury cathode coating by displacement during immersion of a portion of said rotating cathode in a relatively large volume of mercury.

2. In a process for reclaiming uranium values .from an oxidized hydrochloric acid solution of about 3 N concentration and containing UO2++ ions and ions selected from the group consisting of Fe Cu++, Ni++, and Cr+++ ions, the steps comprising continuously passing said solution through the cathode compartment of an operating electrolytic cell having a rotating cathode which is provided with a thin, continuously-replaceable mercury coating and having an anode compartment separated from said cathode compartment by a porous barrier which anode compartment is also filled with a hydrochloric acid anolyte of about 3 N concentration, continuously and simultaneously correlating the rate of flow of said solution through said cathode compartment of the operating cell with the electrolytic current density applied therethrough to promote the reduction of said UO++ ions to U++++ ions and the reduction of Fe++ ions to Fe+++ ions, and continuously and simultaneously replacing said mercury cathode coating with fresh mercury during immersion of a portion of said rotating cathode in .a relatively large volume of mercury.

3. The process as defined in claim 2 wherein said correlation of the rate of fiow of the solution with the electrolytic current density is such that the rate of solution flow is in the range of 1 to 1.17 cc. per minute with respect to a cathode electrolytic current density in the range of 0.1 to 0.3 ampere per cm? and said anoly-te comprises hydrochloric acid of about 3 N concentration.

References Cited in the file of this patent UNITED STATES PATENTS 1,970,973 Palmaer Aug. 21, 1934 (Other references on following page) OTHER REFERENCES Zeitsghrift; fiir Anorganis, :he ,Chemie, vol :57. 0190.8

12 page;s .235, 23,6,(partz of an article; by Rqsenheim ;et ;.a1.);.; Uranium ;-andzAtomic,Power, by 'JBCKKDQ: Men and H. ,C. Dake, Chemical 'Pwblishing po NfiW YOlkwfi 1'941,page 189.

Electrolytic Oxidation and Reduction, by S. "Glasstonesa' et aL, D. Van Nostrand- Co., 1936, pages, 137-, 138.-:v 

1. IN A PROCESS FOR RECLAIMING URANIUM VALUES FROM AN OXIDIZED HYDROCHLORIC ACID SOLUTION OF ABOUT 3 N CONCENTRATION AND CONTAINING UO2++IONS AND IONS SELECTED FROM THE GROUP CONSISTING OF FE+++, CU++, NI++, AND CR+++ IONS, THE STEPS COMPRISING CONTINUOUSLY PASSING SAID SOLUTION THROUGH THE CATHODE COMPARTMENT OF AN OPERATING ELECTROLYTIC CELL HAVING A ROTATING CATHODE WHICH IS PROVIDED WITH A THIN, CONTINUOUSLY-REPLACEABLE MERCURY COATING AND AN ANODE COMPARTMENT FILLED WITH A HYDROCHLORIC ACID ELECTROLYTE OF ABOUT 3 N CONCENTRATION AND SEPARATED FROM SAID CATHODE COMPARTMENT BY A POROUS BARRIER, CONTINUOUSLY AND SIMULTANEOUSLY CORRELATING THE RATE OF FLOW OF SAID SOLUTION THROUGH SAID CATHODE COMPARTMENT OF THE OPERATING CELL WITH THE ELECTROLYTIC CURRENT DENSITY APPLIED THERETHROUGH TO PROMOTE THE REDUCTION OF IONS OF UO2++ IONS TO U++++ IONS AND THE REDUCTION OF THE SAID GROUP TO THE METALLIC STATE ANDD WHICH ARE ABSORBED IN SAID MERCURY CATHODE COATING, AND SIMULTANEOUSLY AND CONTINUOUSLY REPLACING AID MERCURY CATHODE COATING BY DISPLACEMENT DURING IMMERSION OF A PORTION OF SAID ROTATING CATHODE IN A RELATIVELY LARGE VOLUME OF MERCURY. 